A load driving circuit comprises a converting circuit, a converting controller, a load driving modulator, and a charge spike protection circuit. The converting circuit is adapted to be coupled to an output power source and supplies a driving power source to drive a load. The converting circuit has an output capacitance coupled to an output end thereof. The converting controller controls an amount of the driving power source responsive to a current or a voltage of the load. The load driving modulator and the load, connected in series, are coupled to the output end and so the load driving modulator adjusts an electronic state of the load. The charge spike protection circuit is coupled to the output capacitance and at least one connecting node of the load and the load driving modulator to provide a unidirectional charge release path to the output capacitance.